The principal aim of the application is to study the impact of a quality improvement model using academic detailing and electronic medical records (EMR) on adherence with clinical practice guidelines for prevention of cardiovascular disease and stroke in primary care settings. The long-term objective of the research is to validate a method implementing evidence- based medicine in primary care, using an approach combining information tools and behavioral change theory. Investigators from the Medical University of South Carolina's Center for Health Care Research (CHCR) will conduct the study in 22 affiliated Practice Partner Research Network (pPRNet) sites across the United States. Project investigators have developed and refined the model to be tested in this application in previous research. The model is termed "Quality Improvement through Electronic Medical Records (QIT-EMR)." The primary prevention guidelines studied will be screening for hypertension and hypertension control, screening for hyperlipidemia, and hormone replacement therapy for postmenopausal females. The secondary prevention guidelines will be cholesterol lowering for patients with coronary heart disease (CHD) and diabetes mellitus (DM), beta-blockers for patients with a history of myocardial infarction, angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers for patients with heart failure, oral anticoagulant therapy for patients with atrial fibrillation, and glycemic and blood pressure control in patients with DM. The study will be a three-year randomized controlled clinical trial. It will test the hypothesis that practices that receive the QIT-EMR model interventions will have greater improvement in the proportion of patients who receive the primary and secondary preventive interventions and achieve target outcomes than do comparison practices. Data for the study will be obtained from the existing EMR at each study practice. Control group practices will receive information about the clinical practice guidelines, and quarterly reports detailing their adherence with them. Intervention group practices will receive identical information and participate in four practice site visits by study investigators, three investigator meetings, and ongoing communication to implement the QIT-EMR model. A formative evaluation of the interventions will be conducted. At the conclusion of the trial, the impact and cost of the intervention will be assessed.